When riding a triathlon bike, is it better to be in more of a narrow and tall position? Or is a long and low position better?
Which is faster? Also, which is more comfortable for long rides?
Thanks for the opinion/advice!
Not to be the guy who throws out the vague “it depends” answer, but… it depends.
The tall and narrow versus long and low argument is very personal - do you have long legs and a short torso, or short legs and a long torso? Your best bet is to get fit and know your stack and reach. Once you know your stack and reach, you can find a bike that is right for you - the bike that fits will be the fastest and most comfortable for you. Slowtwitch has some good resources for that:
http://www.slowtwitch.com/Bike_Fit/Choosing_a_Tri_Bike_via_Stack_and_Reach/index.html
http://www.slowtwitch.com/Bike_Fit/Tour_de_Bike_Fit_649.html
http://www.slowtwitch.com/stackreach/index.php
http://www.slowtwitch.com/stackreach.html